The man responsible for the signature McDonald's burger, the Big Mac, has died. Michael James "Jim'' Delligatti was 98.

Delligatti was a McDonald's franchisee in Uniontown, Pennsylvania, when he created the burger in 1967 after deciding that customers wanted a bigger sandwich. Demand exploded as Delligatti's sandwich spread to the rest of his 47 stores in Pennsylvania and was added to the chain's national menu in 1968.

The hamburger features two beef patties, a mildly tangy sauce, lettuce, cheese, pickles and onions in a soft sesame seed bun sliced into three layers. The same recipe is used today in the popular sandwiches, which are now served in more than 100 countries around the world.

The original price was 45 cents, compared with an average of about $5 today.

"He was often asked why he named it the Big Mac, and he said because Big Mc sounded too funny,'' his son Michael Delligatti said.

When the burger turned 40, McDonald's estimated it was selling 550 million Big Macs a year, or roughly 17 every second. Delligatti received no payment or royalties for coming up with the burger, the company said.

Delligatti also helped introduce breakfast service at McDonald's, developing the hotcakes-and-sausage meal to feed hungry steelworkers on their way home from overnight shifts in the Pennsylvania mills, his family said.